Mobile computing devices generally include portable devices that allow users to take the device to remote locations and still have the ability to access or process information. Examples of mobile devices may include hand held video recorders, digital cameras, laptop computers, hand-held computers, wearable computers, and portable music players, to name a few. Some mobile devices are capable of communicating information over networks using wireless techniques, such as infrared or radio frequency (RF) signals. In addition to communications, mobile computing devices may perform many of the same functions as non-mobile computing devices, such as powering a display device and displaying information, receiving keyboard input, processing program instructions and user input, and storing and retrieving information from data storage devices. To perform each of these functions involves supplying certain electronic components with an appropriate source of electrical power.
Electrical components, such as displays, processors, and data storage elements, may consume electrical power according to the operations they are performing. Some components can consume significant electrical power even when not performing any productive operations. One by-product of such unproductive power consumption is heat, which is often lost energy that contributes to temperature increases. Another by-product of this unproductive power consumption is an increased energy source requirement. As such, unproductive energy adds to the demands on the power source.
In a typical computing device, a power supply system furnishes the regulated voltage and/or current needed to operate all the electronic components. The power supply system often may draw energy from a source of stored energy. A common source of stored energy for mobile applications is a battery.
In a battery-powered mobile computing device, for example, unproductive power consumption may reduce available run-time. Battery run-time corresponds to how long a device can be operated using the battery as the power source. Run-time can be an important consideration, for example, for mobile computer users who rely on battery power while performing an important task. If the battery runs too low on energy to support the computing device operations, the user must find an alternate power source, such as an AC outlet or replacement battery, or discontinue using some or all of the functions of the device.